Re: Text-spanner text repeated at start of line

[David Kastrup]

Thomas Morley <address@hidden> writes:

> 2015-10-27 15:54 GMT+01:00 David Sumbler <address@hidden>:
>> Regarding
>> \override TextSpanner.bound-details.left-broken.text = ##f
>>
>> In section 3.1.122 of the internals reference, I see 'left.broken' as an
>> item in the 'bound-details' list but with no indication of what it does,
>> nor that 'left-broken.text' is possible and the values that could take.
>> How could I have found this out from the documentation?
>
> Hi David,
>
> well, we have
> http://www.lilypond.org/doc/v2.19/Documentation/notation/spanners#using-the-line_002dspanner_002dinterface
>
> Could you suggest on the bug-list something to improve it?
> I'm a non-native speaker ...
>
> In general, the bound-details-property is a list of lists. With
> possible settings for (pseudo-code)
> '(
>   (left <settings-1>)
>   (left-broken <settings-2>)
>   (right <settings-3>)
>   (right-broken <settings-4>)
> )
> I think, possible key-value-settings are explained quite well in the
> above linked doc.
>
> Of course it's possible but quite tedious to always enter the whole
> list. Therefore, we have the dotted-list syntax for nested properties,
> which modifies a single entry in the (default-)list, like`
> bound-details.left-broken.text'

Dotted-list syntax is decidedly newer than nested properties.  2.18 or
so?

> Btw, there was a problem with reverting overrides for bound-details.

There were all sorts of problems with reverting nested overrides.  The
current version works as expected, though a revert path must exactly
match a previously used override path in order to have an effect.  You
cannot revert sublists of a previous override.  At some point of time,
reality takes its toll.

> David Kastrup fixed it some time ago.

2.19.13, about a year ago.  Not yet available in a stable version.

You'll find that my issue comments and solution sketches on the problem
run from years 2011 to 2014.  This one took a really long time until I
figured out a solution I considered satisfactory in performance as well
as reliability (I probably printed out at least 4 times as much paper
and scribbled over it than for the rest of LilyPond combined).  The
solution also touched some other issues.

At any rate, using overrides on single settings in a nested alist (and
reverting them eventually) is nothing to avoid in current developer
versions but can still be problematic in the current stable version.

-- 
David Kastrup